Two Migration Strategies Anadromous species (salmon, shad) breed in freshwater and grow in the ocean. Catadromous species (eels, galaxiids) breed in the ocean and grow in freshwater - the reverse journey.

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Olfactory Navigation Pacific salmon return to the precise stream where they hatched - guided entirely by olfactory memory of trace chemical signatures imprinted during their juvenile freshwater phase.

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Physiological Switch During smoltification, salmon reprogram kidney function, gill ion channels, and hormone profiles - a complete physiological transformation enabling life in both fresh and salt water.

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Dam Threat Dam construction has blocked access to over 40% of key salmon spawning rivers globally. Diadromous species are among the most rapidly declining vertebrate groups on Earth.

Other Habitats

🌊 Marine Fish 💧 Freshwater Fish 🌿 Brackish Fish 🌍 All Habitats

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